Air assist atomization of the liquid fuel emitted from the tip end of a fuel injector is a known technique that is used to promote better preparation of the combustible air/fuel mixture that is introduced into the combustion chambers of an internal combustion engine. A better mixture preparation promotes both a cleaner and a more efficient combustion process, a desirable goal from the standpoint of both exhaust emissions and fuel economy.
The state of the art contains a substantial number of patents relating to air assist atomization technology. The technology recognizes the benefits that can be gained by the inclusion of special assist air passages that direct the assist air into interaction with the injected liquid fuel. Certain air assist fuel injection systems use pressurized air, from either a pump or some other source of pressurization, as the assist air. Other systems rely on the pressure differential that exists between the atmosphere and the engine's induction system during certain conditions of engine operation. It is a common technique to mount the fuel injectors in an engine manifold or fuel rail which is constructed to include assist air passages for delivering the assist air to the individual injectors.
Prior techniques used to construct the air assist injector assemblage are tedious and imprecise. One technique requires pressing on a thimble, then pressing on an atomizer to an injector valve tip until the press bottoms out on the body. The injector was then removed from the press and placed onto an air flow test fixture to measure flow. If the flow was higher than the specification range, the injector was removed from the fixture and placed back on the press to crush down further. The procedure was repeated until the air flow was within the specifications. Obviously, this procedure is very time consuming, as well as very costly. Furthermore, an inadvertent overpress would force the injector to go below the specifications, rendering the injector unusable.
It is seen then that there exists a need for a manifold press tooling device which enables internal flow measurements to be made during the press fitting of the atomizer to the injector.